Safety gas cut-off.



H. HQ HUSTEAD. SAFETY GAS CUT-OFF. APPLIOATIN FILED AUG. 9, 1910.

Patented July 23, 1912.

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@M @www H. H. HUSTBAD.

SAFETY GAS GUT-OFF.

APPLIOATIONl IILBD AUG. 9, 1910.

Patented July 23, 1912.

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vTo all whom t may concern:

' HALLA' E. HUSTEAD, OF BROWN, WlES'l` VIRGINIA.

SAFETY GAS CUT-oFF.

v Specification of Letters Patent.

Application` led August 9, 1910. Serial No. 576,373.

v Beit known that I, HALLA H. HUs'rEAD, a

"citizen of the United States, residing at' Brown, in the county ofHarrison and State of West Virginia, have invented new and usefulImprovements in Safety Gas Cut- Oii's, of which the following is a.specificat-ion.v d

This invention relates to a safety gas cutoff for use between a gas mainand thegas lservice pipe of a house for automatically cutting oft' thesupply'of gas to the house when the pressure of the gas in the mainis-materially reduced or cut off. i

The object of the invention 1s to provide a simple, eifective andyreliable device of this character which will positively cut off.communication between the main and service pipe under the conditionsabove mentioned and preventA the flow of gas to the service pipe whenthe normal pressure in the main is resumed until the cut-off is manuallyre-` set for furtherv operation, thus avoiding all liability of dangerto the occupants of' a house by the resumption of the flow of gasthrough open burners.

The invention consists of the features of construction, combination andarrangement of parts, .hereinafter fully described and claimed,reference being had to the accompanying drawings, in which l Figure 1 isa view in side elevation of a safety cut-ofi embodying my invention,shown arranged in position for use. Fig. 2 is a vertical longitudinalsection of the same, with the valve open for service operation.

lFig. 3 is asimilar view on an enlarged scale of the valve ailddiaphragm arranged for service operation as in Fig. 2. Fig. 4 is asimilar section showing the valve closed to cut off the flow of gas tothe service pipe.

Referring to the drawings, 1 designates l the gas main or a supply pipeleading therefrom, and 2 the house service pipe, between which pipes myimproved cut-off is interposed. The cut-off comprises a conducting pipe3 having terminal T-couplings 4 and 5 connecting the same with the pipes1 and 2. Connected with the coupling 4 and leading upwardly therefrom isa branch pipe 6 communicating with a pressure `chamber or casing 7 inwhich is arranged a diaphragm 8 or its equivalent, such as a pistonofany preferred type. The casing4 8 comprises 'a body portion divided orformed of two sections 9 and 10 and end heads 11 and 12 coupled togetherby bolts 13. The diaphragm 8, which consists of a body of fabric orother .suitable material, is clamped at its marginal ledge between theproximal edges of the sections 9 and 10 and separates Patented Julyzs,1912.

the casing into4 two compartments 14 and 1,5, the pipe 6 communicatingwith the compartment 14, as shown.

Attached centrally to the diaphragm 8 is a rod or stem 16 which extendsat its rear end through the head 11 and through a stuffingbox 17 carriedthereby and carries a washer 18 and a retaining nut 19. Between thestuiiingbox 17 and the washer '18 a coiled spring 20 surrounds the stemand exerts its expansive pressure upon the washer lto normally holdthe'diaphragm against movement toward the compartment- 15 under thepressure of'the gas thereon within the 'compartment 14. The tension ofthe spring may be regulated by adjusting the nut 19 so as to adapt thediaphragm to have movement orv iiuctuate under the gas pressure when thepressure in the main is at or above normal service pressure, the springat all` other times holding the diaphragm in normal position againstmovement. The opposite end of the stem 16 projects outward through anopening 21 in the head 12 in which it is freely movable, the openingbeing of such size as to ypermit free inlet and exit of air to and fromthe compartment 15 to enable-the diaphragm to havea sensitive action.The extremity of such end of the stem is formed with avlongitudinal slot22 connected by a slotted link 23 with an eye 24 on the outer rear endof the stem 25 of the cut-oit' valve 26. The valve 26 is arranged withina casing 27 forming a coupling uniting two branch pipes 28 and 29forming a bypass between the coupling 5 and the pipe 3 at a pointbetween said 'coupling 5 and the coupling 4, a stop valve 30 beingarranged in said pipe 3 ,between the branch 28 and coupling so that thedirect .Howy of gas from the pipe 3 to the pipe 2 may be cut off tocause the gas to pass normally through the bypass, while at the same'time enabling a direct supply of gas to be obtained in the event ofcasual derangement of the valve 26. The valve 26 is movable inwardly toclose against a seat 31 and 1s movable outwardly from said seat for the'flow of gas from the branch pipe 28 to the branch pipe 29 under normalservice conditions, the direction of closing movement of the valve beingsuch as to adapt it to be drawn against its seat by the action of thespring 20 1n restoring the diaphragm to normal position inthe event ofthe diminishment of pressure in the chamber 14 from the cessation ormaterial decrease of pressure of the gas in the main. The pipe 28 isconnected with the pipe 3 and the valve 30 by a coupling 32, whichconnects said coupling 32 with the coupling 5, and the pipe 29 ispreferably composed of two main sectionsunited by a coupling 33, suchcouplings adapting the parts to be conveniently assembled for use anddisassembled for repairs or replacement in the event of injury thereto,as well as to permit free access to the valve 26 for cleaning whenevercircumstances require.

The slotted portion 22 of the stem 16 and the link 23 form a slip joint,lost-motion or slot and pin connection between the stem 16 and the valve25 to adapt the valve to be positively closed by the spring 2O when thediaphragm is relieved of normal pressure, and to prevent movement of thevalve to open position by the subsequent action of the diaphragm in theevent of the restoration of normal pressure in the main, thus requiringthe valve, after having been once closed, to be manually opened beforethe gas can again pass from the main to the service pipe.

Figs. 2 and 3 show the position of the parts when the valve is open fornormal service operation, from which it will be seen that the diaphragm8 is-pressed forward' by the pressure of the lgas within lthecompartment 14, thus compressing the spring 20, and that the forwardmovement of the valve to open position disposes-the rear end of the link23 adjacent the forward end of the slotted portion 22 of the stem 16,whereby the diaphragm is permitted, without affecting the 4valve 26, tofluctuate slightly back and forth under vslight variations of thepressure in the main, the link playing loosely inthe slot 22. When,however, the pressure in the main is materially reduced or entirely cuto', the spring 22 rest-ores the diaphragm to normal position, and in sodoing moves the stem 16 rearwardly, causing the forward end of theslotted portion 22 to engage the link 23 and to move the valve 26 toclosed position, thus cutting ofr"V communication between the main andservice pipe through the bypass. As the valve 30 yunder normalconditionsv is also closed, direct communication between the mam andservice'pip'e will also at this time be entirely cut off. If thereshould be a resumption of normal pressure in the main under theseconditions, the diaphragm will again be tion, therefore, can only berestored by the adjustment of the valve to open position by manualoperation, by whichthe parts willbe returned to the position shown inFigs. 2 and 3, so that after the valve 26 is once closed automaticallyit will remain in closed position-uninfluenced by the subsequent actionof the diaphragm until it is manually reset to open position.

It will thus be understood that if at any time when the burners in ahouse are in use and the flow of vgas through the main is arrested fromany cause, as through the shutting down of the gasplant or the cut oifof communication between the gas reservoir and the main, the automaticcut olf will be instantly set vinto operation to close the valve .26 andclose communication between the main and the house service pipe, so thatif the flow of pressure in the main should be suddenly restored the flowof gas 4 into the house through the open burners will be prevented. Itwill be apparent that the occupants of a household will be warned in anobvious manner of the condition of affairs and the fact that the safetyvalve lhas been closed, and may restore normal service conditions bymanually resettingv or opening the valve.

-I clalmz- In an automatic safety gas cut-ofi', the combination of aconductor, a valve casing therein, a non-rotary sliding valve in saidcasing manually adjustable to open position in the direc'tion of thecourse of flow of the gas, a non-rotary sliding controlling stemAbetween said stems, the construction being such that whenthe valve isopen a coupling In testimon whereof I aix my signature enga ement is'afforded whereby the valve vin presenceo two witnesses. may zh closedthllgouglh the retragtin of the c contro 'ng stem t e action o t e sprin5 means whenl the diphra is relieved frol l HALLA H' HUSTEAD pressure,vwhile, when t e valve is closed, Witnesses: said controlling stem ispermitted to `have I. L. DAvIsvsoN,

movement without opening'said valve. l A B. L. RnTENHoUsE.

